Previous aerial advertising devices, all of which have been towed by aircraft, have been concerned with two major areas. The first is the ease of storage and set up, and the second is the stability of the body of the device during actual use.
Prior aerial devices, such as banners, which can be rolled up for storage, have utilized simple tubes running the length of the banner, so as to give added rigidity to the device during use, as typified in U.S. Pat. No. 1,794,828.
Other aerial advertising devices, as illustrated in U.S Pat. No. 1,973,205, have consisted of various desired shapes constructed around a tapered tubular wind tunnel with a fixed restricting choke in the aft end of the device, which increased drag and gave the device a more horizontal appearance when towed behind a fast moving airplane.
Wind velocities often caused the outer surfaces of a tubular aerial device to flutter and oscillate when towed behind a fast moving airplane, which diminished desired visual impact. As shown in U.S. Patent No. 2,238,876, a rigid but somewhat bendable set of copper wire convolutions held the front end in an open position. Wire mesh, placed across the opening of the aft end providing a fixed choke, results in greater stability of the device side walls during use.
A later method of reducing the flutter and oscillation of an aerial device side walls, when towed by a fast moving airplane, was achieved when a mesh or net fabric was used for the entire body of the aerial device, as illustrated in U.S. Pat. No. 5,026,073. In this particular patent, an adjustable choke was also used to vary the intensity and amount of air which passed through the side mesh walls of the device.